Frequencies for first 10,000 rows of f_u_vbac variable in natl2008 dataset :

    Vaginal |
      after |
  C-Section |
 (ume_vbac) |
          U |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         92        0.92        0.92
          1 |      9,908       99.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 May 2016